How Much X-Ray and Gamma-ray Data Are in the HEASARC's
Archive?

Last Update: 2018 February

As of this date, there were about 100 Terabytes (TB = 1 billion kB)
of X-ray and gamma-ray data in the HEASARC's high-energy archive, compared to
85 TB in February 2017, 38 TB in April 2012, 1.8 TB at the start of 2000 and
0.3 TB at the start of 1995. Growth in the last 6 years has been mostly due to
the increasing size of the Swift
(now 28.5 TB), Fermi (now 20.1 TB), INTEGRAL (now 14.8 TB), and XMM-Newton
(now 8.8 TB). Other HEASARC missions which are currently being archived
include the NICER (now 3.6 TB), Chandra (now 2.6 TB) and NuSTAR (now 1.8 TB)
missions. Data volumes from previous missions are typically much smaller:
Hitomi (0.76 TB), RXTE (2.7 TB) and BeppoSAX (1.3 TB),
except for the Suzaku (11.1 TB) mission.